Technological advances in telecommunications systems have automated activities that had required human intervention. For example, in U.S. Pat. No. 4,054,756, processing of special services calls, such as person-to-person, collect, credit card and bill to third party calls, are automated to eliminate the need for a human operator to handle such calls. U.S. Pat. No. 4,761,807 discloses a system for transmitting audio messages between parties, thereby eliminating the need for a human receptionist. In another example, the automated system of U.S. Pat. No. 5,058,152 may serve as an intermediary between a subscriber to the system and the subscriber's potential customers, again eliminating the need for the subscriber to employ a receptionist.
Advances in technology have also resulted in the use of telecommunications systems for a myriad of purposes probably not contemplated by Mr. Alexander Graham Bell. Telemarketing is one such use. A telemarketing system in which an operator can view the response of the individuals called by the system is disclosed in U.S. Pat. No. 4,160,125. In addition to telemarketing, callers are able to play interactive games via the telephone interface game control system disclosed in U.S. Pat. No. 5,218,631. Goods and services can be marketed by telephone when using the invention disclosed in U.S. Pat. No. 4,071,698. Stock brokers can automatically notify their customers of changes in the market via the mass announcement systems disclosed in U.S. Pat. Nos. 4,554,418 and 4,942,616. Also, pre-recorded messages can be transmitted in the announcement systems of U.S. Pat. No. 4,446,336.
Another attractive use of the telecommunications system is a mass communication system for communicating important messages to the public. For example, it may be desirable to provide an automated system which can inform the public of an impending emergency or a disaster, or to provide a public service message. For mass communication purposes, the system must retain a database containing the telephone numbers of the public to be serviced by the system. Also, since it is unlikely that all members of the public need to be provided with the informative message, a means must be provided, and data must be accessible, for selecting certain criteria associated with the system's subscribers. For example, information about an impending emergency, such as a tornado warning, need only be transmitted to those in a particular locality. Therefore, emergency alert systems have been developed, such as the MINUTEMAN public alert system offered by United Signal of America in Indianapolis, Ind., which allows one to select a particular geographic area to be informed of an alert or emergency situation.
When selecting a geographical area, various methods are known in the art for associating a telephone number with the corresponding location. One simple method involves associating the telephone number with a predetermined zone designated by an alphanumeric such as A-1 or B-2 which corresponds to sections on a map. In the aforementioned MINUTEMAN public alert system, X-Y coordinates are associated with each phone number in the system's database. The operator may prepare a map showing geographic zones associated with each coordinate area.
One shortcoming of prior art systems using geographic zones selection as a criteria for determining to whom the message is to be sent occurs when the zone to be selected is of a size significantly different from the size of the grid employed by the system. Though the MINUTEMAN system described above allows a grid size to be redefined, when operating in an interactive mode, if a large geographical area is to be contacted by the system, prior art systems require the operator to enter a list of grids to encompass a large enough area. The size of the grid in prior art systems is therefore critical. To avoid encountering an unacceptable time delay by entering such a list (for example, it may be imperative that the message be communicated within a very short period of time due to the nature of the message), the grids are likely to be sized to err by reaching those who need not be informed rather than risk the inability to reach anyone. Therefore, it is desirable to provide a system providing greater flexibility to the system's operator for the selection of the Geographic Zone.
One of the shortcomings associated with many mass communication announcement systems such as public alert system is the inability of the public to control its participation in the service. Given the increased frequency for which the telephone is being used for telemarketing and solicitations, many people are resistant to participate in an automated service over which they have no control, particularly if such a service is to be provided by an organization, such as the police department, which is funded, at least in part, by taxes they have paid in the community. Thus, even though the service may be beneficial to the community, an individual may wish not to participate or to limit its participation. For example, the individual may only wish to participate during certain times or days, or to only be informed of certain occurrences. If, for example, the system is used by a law enforcement agency for informing the public of a recurring problem in the area, such as the theft of children's bicycles, not every individual or residence in the designated geographical area are interested in receiving such a message. There is also the possibility that the members of the household may wish to screen certain members of the residence from receiving such calls. A parent, for example, may not want the message to be transmitted to a six-year old child in the home. Therefore, it is desirable to provide a mass communication announcement system which permits the public to individually control its level of participation in a service implementing the system.